"It's something we haven't done," the actress who plays Deputy Jo Lupo said in an exclusive TV Fanatic interview. "It will be a new mission."

Mostly mum on specific spoilers, Cerra added that "something crazy" goes down on pretty much every episode. She's especially excited for fans to see the installment that revolves around hallucinations.

Overall, the character of Deputy Lupo has come along well in four years.

"She started off as naive and narrow-minded," Cerra said. "But she's opened up as a human being and really moved up to her own position of power. She's been given a lot more responsibility and developed a lot of layers."

The same can be said for Eureka, which has developed a cult following over the years. Cerra credits the success to a cast that "laughs everyday, from the moment we arrive to the moment we leave work."

"Our crew is hysterical," too," she says. "They've been working together since The Dead Zone, more than 10 years. That's why the series translates so well. It really, really shows on screen."